An original electrochemical pathway for the synthesis of porphyrin oligomers.

An electrosynthesis process has allowed the formation of four oligomers, containing three, four, or five macrocycles. This method is based on the nucleophilic attack of porphyrins substituted by several pendant pyridyl groups to the electrogenerated radical cation of zinc β-octaethylporphyrin (ZnOEP), according to an ECEC processes. Thus, a control of the number of macrocycles and of the geometry of the oligomers can be performed. These new compounds have been characterized by HRMS as well as (1)H NMR, UV/Vis, and fluorescence spectroscopy, and electrochemistry. The results show a strong influence of the pyridinium spacers on the macrocycles.